2014-2015 probably was a scary time to be aboard the ISS, though not for the usual reasons. They were worried about supplies running low, at least somewhat. There was quite the string of bad luck.

  1. Cyngus CRS Orb-3 blew up seconds into flight.
  2. Progress M-27M had a spacecraft control issue and failed to reach the ISS.
  3. SpaceX CRS-7 blew up shortly before MECO.

How close to running out of supplies was the ISS crew after these failures? How many months did they have left, both on normal rations and minimal rations?


1 Answer 1


Hobbes' answer to How long can a 2 person crew survive on ISS totally cut from Earth? has links to articles that include NASA press releases from around that time.

In Progress Failure Puts Burden on Upcoming Resupply Missions (after the M-27M failure), Jeff Foust wrote

In a presentation to a NASA Advisory Council panel here April 8, NASA officials said food supplies on the ISS would reach a threshold called “reserve level” on July 24, and go to zero on Sept. 5. That assumed that the station received no more supplies beyond a SpaceX Dragon cargo mission launched to the station in April [CRS-6 - Erin].

The other major limiting consumable is a solid waste container known by the Russian acronym KTO. Without additional cargo missions beyond the Dragon flight, KTO supplies would reach the reserve level July 20 and be exhausted on Sept. 2. Other consumables, including water, would not reach reserve levels until later in the year or early 2016.

After Progress M-28M arrived, Jeff Foust wrote in "Progress Arrives At Space Station, Easing Supply Concerns" for Spacenews that those estimates had been revised:

Michael Suffredini, NASA ISS program manager, said at a June 28 briefing that the station still had enough basic supplies, including food and water, to support its crew through October. The supplies on this Progress, he said, would extend that date by about a month.

The Spacenews article about the HTV-5 launch indicated that

The arrival of the HTV will further ease concerns about the station’s supply of food and other consumables that were under strain by a series of cargo mission failures in the last year. The additional cargo on board the HTV will extend station’s supplies through at least the end of the year.

In articles about Progress M-29M and Cygnus OA-4 I don't see any further estimates, indicating that the concern about continued supply flights had died down by that point.

However, treating the supply problems as a starvation concern is hyperbolic. This was always a loss-of-mission concern rather than loss-of-crew; if supplies had not arrived in time, the astronauts would have left the station in the Soyuz available to them and returned to Earth.

  • 3
    $\begingroup$ They're being purposely euphemistic about it, but KTO is the fecal waste container for the toilets. At that time, the US segment was using a toilet that was bought from the Russians. $\endgroup$
    – user71659
    Commented Mar 20, 2023 at 2:19
  • 1
    $\begingroup$ It's interesting that they converted the KTO metric into a positive value and is able to just list it along other supplies. The KTO is most likely just a container getting filled up with crap and they need it removed, so the "supplies" is actually remaining space. $\endgroup$
    – Nelson
    Commented Mar 20, 2023 at 2:34
  • $\begingroup$ y'know, I was reading it as the KTO just getting full too, but I'm honestly not sure if there are maybe supplies getting used up too (toilet paper, sanitizer, astronaut litter?). How was KTO offloaded? Drained into a Progress? $\endgroup$
    – Erin Anne
    Commented Mar 20, 2023 at 2:40
  • 6
    $\begingroup$ The KTO is a solid metal container that's sealed when full, about 21 uses, and disposed of. It's the tank under the seat. The container is rigid metal in order to contain the gas pressure due to bacterial decomposition of the feces. $\endgroup$
    – user71659
    Commented Mar 20, 2023 at 3:09
  • 4
    $\begingroup$ @Starshipisgoforlaunch You can't just change a quote from a source. Be careful with your edits. Rolled back. $\endgroup$
    – Erin Anne
    Commented Mar 21, 2023 at 11:39

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