How Long Can the ISS Really Last?

How long can the International Space Station really operate – until 2020, or 2028 or beyond? I recently had the chance to talk with Mark Uhran, NASA’s Assistant Associate Administrator of the ISS. We were both attending a conference on water sustainability at Kennedy Space Center, but Uhran took the time to talk with me about the state of our space station, NASA’s new budget and how that might affect ISS operations, and — speaking of water — how is the urine recycling system working these days?

You can also hear an audio version of this interview on the March 28 edition of 365 Days of Astronomy.

Universe Today: How are things going as far the extension of the ISS? I heard there was recently a meeting with the international partners where they said it could be extended to 2028 if need be.

Mark Uhran. Credit: NASA

Mark Uhran: We’ve made the decision in the United States as part of the President’s budget proposal to Congress, so we’re over the hump here in the US. And then we began a series of meetings with the partners starting in Japan last week. Of course each of the partners has been working with us for the past 12-18 months, but they are fully prepared to approach their governments and ask for an extension. There are no technical obstacles to extending to at least 2020, and we’re also going to be doing an evaluation to what the ultimate lifetime of the ISS might be. That evaluation is in process. So we’re looking at whether we can go as long as 2028, but that remains to be seen.

Universe Today: Since we’re here talking about water, how are things going with the recycling system up there on the station. I know there have been some glitches here and there.

Uhran: The station has been a real testbed for developing regenerative water and air technologies. We knew at the time deploying these systems they would be in a testbed mode, and it would probably take about a year to shakedown all the systems and we are making steady progress towards doing just that. All the systems are working today – that’s not to say they will be working tomorrow. We certainly do expect them to go up and down throughout the course of the year as we fine tune them and work out the details. By the end of this year we hope to add a Sabatier (carbon dioxide reduction system) reactor that will allow us produce yet further water on orbit.

NASA"s Water Recovery System for the ISS. Credit: NASA

Hauling water is a very expensive proposition for us. Once the Sabatier is up there later this year, we’ll have basically the entire designed system deployed and I’m confident by this time next year we’ll have worked out all the filtration issues, the film formation issues, and precipitant issues and we’ll have this tuned so that it is basically available 90% of the time, which is an outstanding availability rate. So, this has been very worthwhile from our point of view not just because of the cost of hauling water to the space station but for the implications for human exploration beyond low Earth orbit.

Universe Today: The new NASA budget, which eliminates Constellation, how do you see that affecting space station operations?

Uhran: Well, space station is relatively small factor in that new budget. We’ve been extended, which is a major achievement from our point of view. But in terms of financial constraints, we are pretty well prepared now to go ahead and operate until the end of the decade, as well as to ramp up our research program on the station. With the assembly process being completed, the crew time now becomes available for supporting research. So most of our activities this year are geared towards repositioning our utilization program so that when the shuttle stops flying and the commercial cargo resupply services begin we are ready to ramp up that program aggressively, and that’s going very well.

Universe Today: I’ve been here at Kennedy Space Center for about a month and a half and a lot of the people here are talking about a possible extension for the space shuttle program. What are your thoughts on that?

Uhran: Well, the shuttle was certainly required for the assembly phase because we were hauling 20 metric ton elements up to orbit. It literally is the equivalent of a six-wheeler truck. But for the utilization phase, we can continue to maintain and operate the space station at much lower supply rates; typically 3 metric tons on a half a dozen to a dozen times a year. So there are other vehicles both that our international partners bring to the table as well as we’re hoping that the commercial US industry will demonstrate in the next 12-24 months that really will meet our needs once those are available. So although we’d all like to see the shuttles continue to fly forever, we really don’t have a requirement on space station for that kind of relatively heavy lift capability.

A close-up look at the Solar Alpha Rotary Joint. Credit: NASA

Universe Today: Another issue that has been sort of looming for the space station is the solar alpha rotary joints (SARJ). Any progress on understanding why they aren’t working as hoped?

Uhran: Well, they are working now. And the failure analysis has been completed. So we know the root causes of the problem. The most challenging mechanisms in any spacecraft system are rotating mechanisms. So the control moment gyros, the solar array rotary joints, the thermal radiator rotary joints – they are all rotating mechanisms. And we’re passing power through those mechanisms, which adds to the complexity. So we think that we have all these under control. It turned out with the SARJ that we have determined the cause of the failure, and we’re doing, really two things. We’re operating the system more gently – we ramp it up more slowly, we stop it more slowly. That doesn’t put as much load on the system. And we find that is applicable to all our systems. The more gently we can operate them the less loads they bear and the longer their lifetime. So we’ll be operating the system more gently and we’ll be lubricating them more regularly. So between those two approaches, we’re pretty confident we won’t have any more problems with the SARJ. We do have a couple of tricks in our pocket in the case that we do see further problems but we think we can get there with the two remedial actions we’ve got now.

Universe Today: To do the lubrication requires a spacewalk?

Uhran: It’s an EVA based activity, yes. It is relatively simple. And not even that time consuming. We were lubricating before, we’ll just increase the frequency.

Thanks to Mark Uhran for taking the time to talk with Universe Today. For more information on the International Space station, visit

Mir’s Fiery Re-entry, March 23, 2001

The storied history of the Mir space station includes collisions, a fire, and political change. But it also consists of unprecedented long-duration spaceflights and scientific studies – and without it, the International Space Station may never have been built. Nine ten years ago, the journey of the 15-year-old Russian space station ended. On March 23, 2001, Mir re-entered the Earth’s atmosphere near Nadi, Fiji, and fell into the South Pacific. The planned and controlled re-entry began when the engines of a cargo ship docked to Mir were fired causing the station’s orbit to brake, starting Mir’s descent. The video here shows both real and computer generated images of the breakup of the 143-ton station as it descended to Earth.
Continue reading “Mir’s Fiery Re-entry, March 23, 2001”

Space Station Pictures


Here are some space station pictures. We’ve already done photo galleries of the International Space Station, but let’s take a look at some different stations as well:

This is a picture of the Mir Space Station, launched by Russia. This photograph was taken by the crew of STS-89 on the space shuttle Endeavour.

Space Station

Here is a recent image of the International Space Station captured by the crew of STS-129. It shows how much of the construction has now been completed.


This is a picture of Skylab, the United States’ first space station. It was in orbit from 1973 to 1979, and was visited by 3 crews of astronauts.

Stanford Torus

And maybe some day we’ll live in a futuristic space station like this. It’s called a Stanford Torus, and rotates to provide the people living inside an artificial gravity.

Bigelow station

This is an artist’s impression of a future space hotel developed by Bigelow Aerospace. The various modules are inflated and connected together. Test versions of the modules have already been sent into orbit.

We’ve written many articles about the International Space Station for Universe Today. Here’s an article about how you can track the International Space Station, and here’s an article about a how a radio operator was able to communicate with the station.

If you’d like more info on the station, check out NASA’s mission page for ISS. And here’s a link to NASA’s human spaceflight page for the station.

We’ve also recorded an episode of Astronomy Cast about the space shuttle. Listen here, Episode 127: The US Space Shuttle.

International Space Station Viewing

Now that it’s mostly complete, the International Space Station is the brightest human-built object in space. It’s easy to see with your own eyes, the trick is knowing when to step outside and look up to see the station go overhead. If you do get your timing right, you’ll see the station as a bright star moving quickly in the sky. It only take a couple of minutes to pass through the sky above your house. Want to see the station for yourself? Here are some resources for International Space Station viewing.

The best place to go is NASA’s Human Spaceflight tracking page. This shows you the current location of the International Space Station, the Hubble Space Telescope, and any space shuttles currently in orbit.

So that shows you where the space station and shuttles are right now, but how will you know when they’re going to be passing over your part of the Earth?

NASA has a page for sighting opportunities. You can either choose your location from a list of common locations around the world, or you download an application that lets you pick your specific spot on Earth. It will then tell you the exact times ISS will be passing overhead.

If you’ve got an iPhone, check out the ISS Visibility App. This tool will calculate the next times you’ll be able to see the ISS pass overhead.

You can also use a great service called Heavens Above. This will also show you the current location of satellites, as give you times when ISS will be passing overhead.

We have written many articles about the International Space Station for Universe Today. Here’s an article about how ISS is now visible in the daytime.

We have recorded an episode of Astronomy Cast about the space shuttle. Listen to it here, Episode 127: The US Space Shuttle.

ISS Canadarm2 Grabs Resupply Ship

In a true display of international cooperation, American flight engineer Nicole Stott, using Canada’s Canadarm2, captured the Japanese H-II Transfer Vehicle (HTV), with help from Belgium’s Frank DeWinne and Canada’s Robert Thirsk, under the direction of Russian ISS commander Gennady Padalka. The unpiloted HTV arrived at the International Space Station Thursday and later was attached to the Harmony node at 6:26 p.m. EDT. The HTV launched on Sept. 10, and took seven days to reach the ISS so controllers could run various tests and demonstrations on its maiden voyage.

“We had an amazing time doing this,” said Stott, “and we’re so happy to have this beautiful vehicle here. We look very much forward to going in tomorrow and finding all the supplies that I’m sure you’ve stored there for us.” The crew then offered a toast to the new vehicle with their recycled water drink bags.

Stott only had 99 seconds to latch onto the cargo ship before it moved past the station and into another orbit. It came to with nine meters (30 feet) away from the lab before going into free drift so it could be grabbed by the arm.

The crew will open up the HTV on Friday afternoon.

The HTV can bring up to six tons of supplies to the ISS, and will be used to dispose of spent equipment, used clothing, and other waste material when it later undocks and burns up the Earth’s atmosphere during re-entry.

The success of the HTV is crucial for station re-supply, especially when the space shuttle is retired.

“After the space shuttle starts to fade away, we will take over responsibility to bring stuff up to the space station. We’re really looking forward to the success of this mission,” Japanese astronaut Soichi Noguchi, who is scheduled to launch to the ISS in December, said before HTV-1’s arrival.

Source: NASA

ISS Tracking

The International Space Station, or ISS, is the largest object every built by humans in space. And because it’s so large, it’s also very bright; easily visible with the unaided eye. The ISS also follows an orbital track that takes over different parts of the Earth. That means if you know the right time, you can go out and watch the station pass right over. But you need to know the right time, and that requires some kind of ISS tracking tool. Let’s take a look at some ISS tracking tools you can use to tell you when you should head outside and look up.

The best place to track ISS is from NASA’s human space flight ISS tracking page. This site will tell you the current location of the International Space Station, and space shuttles currently in flight, and the Hubble Space Telescope. The problem is that this tells you where the space station is right now, and not when it’s going to be passing through your skies… at night.

A better tool for that is the ISS sightings page. You download an applet that lets you put in your place on Earth and it gives you some upcoming dates and times that the station will be passing overhead. There’s also a quick drop down box, where you can select your location from many places in the world.

Another great tool is Heavens Above. It allows you to track the current position of thousands of satellites, including ISS and the space shuttles, when they’re in orbit.

So use one of these tools for ISS tracking, and then head outside and see if you can see the station with your own eyes.

We have written many articles about the International Space Station. Here’s an article about how you can actually see ISS in the daytime; it’s just that bright. And here’s an image of ISS and the shuttle transiting the Sun.

We have recorded an episode of Astronomy Cast that talks about the Space Station’s orbit.

Britain Proposes New International Space Station Modules


British scientists hope to improve living conditions on the International Space Station (ISS) by designing a new addition: the Habitation Extension Module (HEM). Although the plan is currently unofficial, it is hoped the proposal will get accepted and built for a 2011 launch. This would be a massive victory for UK space aspirations, as the nation currently does not have its own space agency and depends on project collaboration with the European Space Agency (ESA) to develop new space technology. The new HEM design features the UK national flag, the Union Jack, perhaps a symbol for the beginning of a British foothold in space.

The proposed habitat design would actually consist of two modules attached to the Node 3 segment of the station. Intended to provide extra accommodation for six crew members (the station currently holds a complement of three astronauts), this design should be welcomed as the ISS is scheduled to accommodate six people in 2009, signifying that the station will move into a “fully operational” phase of its construction.

As the Space Shuttle would have retired by the time HEM is sent to the station, launch will depend on the Russian Soyuz-Fregat rocket, and final approach to the station would use a built-in propulsion system. In addition to the module, three tons of supplies will be on board, stocking the ISS with food and equipment.

The proposed design will be 12.5 feet in diameter and 18.7 in length, adding a total of 3,531.5 cubic feet of living space. This 24% increase in space from the current living volume of 15,000 cubic feet would surely be a welcomed relief to the ISS occupants, making our only space station a more comfortable place to live and work.

The project would come with a pretty heavy price tag. Convincing the UK government to invest approximately £1 billion ($2 billion) in the construction and running of the module till 2015 might, however, stall the British desire for a strong presence in space.


A New Supply Ship for the ISS


The International Space Station (ISS) depends on regular deliveries of food, air and water, as well as equipment and spare parts to keep the station and its occupants happy and in peak operating condition. Of course, the space shuttle brings supplies on its visits for construction and crew exchange missions, and the Russian Progress spacecraft faithfully brings supplies and equipment to the station approximately every six months. But beginning in February 2008 the ISS will have a new supply ship: Europe’s Automated Transfer Vehicle (ATV). The first of seven planned ships, known as the “Jules Verne,” is currently undergoing fueling to ready the craft for its journey to the space station. Launch is tentatively scheduled for February 22.

The ATV pressurized cargo carrier is based on the Italian-built Multi-Purpose Logistics Module (MPLM), (aka Leonardo, Donatello and Raffaello) which has already been carried to the station via the space shuttle as a “space barge,” transporting equipment to and from the station. The ATV, which is equipped with its own propulsion and navigation systems combines full automatic capabilities of an unmanned vehicle with human spacecraft safety requirements. Its mission in space will resemble the combination of a tugboat and a river barge.

Every 12 months or so, the ATV will haul 7.5 tons of cargo to the Station 400 km above the Earth. The ATV will launch on board a Arianne 5 rocket from Kourou, French Guiana. An automatic navigation system will guide the ATV on a rendezvous trajectory towards ISS, to automatically dock with the station’s Russian service module. The ATV will remain docked to the station as a pressurized “waste basket” for up to six months until its final mission: a fiery one-way trip into the Earth’s atmosphere to dispose of up to 6.5 tons of station waste.

The ATV is a cylinder 10.3 meters long and 4.5 meters in diameter. The exterior is covered with an insulating foil layer on top of anti-meteorite Whipple Shields. The X-shaped extended solar arrays look like a metallic blue wings. Inside, the ATV consists of two modules, the propulsion spacecraft and the integrated cargo carrier which docks with the ISS.

The ATV’s will become especially important during the time period between after the shuttles are retired and before the next generation of US space craft, can bring supplies and crew to the station. The ESA also sees the ATVs as a way for Europe to pay its share in ISS running costs. Depending on the operational lifetime of the Space Station, ESA will build at least 7 ATVs.

Original News Source: ESA Press Release