# Cost of an EVA on the ISS?

What does it cost for an astronaut to spend an hour outside the ISS, in terms of

• astronaut time
• mission preparation time
• ground support personnel
• space suit "rent" (?)

Does this cost vary for a Russian/European/American cosmo/astronaut?

Regarding cost of space suits, according to this comparison of US and Russian spacesuits (EMU and Orlan respectively), EMUs are returned to Earth every 25 EVAs for refurbishment, whereas Orlans are used 12 times then destroyed (!). For the price of an EMU I have seen quotes between 2 and 12 million USD. No idea how much the return to Earth and refurbishment cost, nor how much an Orlan costs.
As you said, the astro/cosmonauts' time spent in EVA preparation, donning, and doffing, is all time during which they are not "productive", and therefore that has to be taken into account when computing the price per "productive" astronaut work. Any idea how much time these would take?
Finally, do you have any idea how many more people sit on console during EVA compared to a normal situation?
Thanks!

• At least some cost metrics that actually makes sense! Feb 16 '16 at 16:41
• Do you want the delta cost for an hour of EVA versus the cost of an hour of an astronaut looking out the window? Otherwise just divide annual program cost by number of hours in a year. Feb 16 '16 at 17:05
• @OrganicMarble I think this is one of the few times where man-hour is actually a reasonable metric to use.
– user
Feb 16 '16 at 18:31
• @ventsyv EVAs are enormously expensive. Consider the amount of effort spent planning and training. Consider that EMU parts (especially gloves) are limited life items, so each EVA takes away useful life of that part. Consider that even a brief, two-hour EVA requires quite a bit of overhead time for the crew for prebreathe, don, and doff. Consider that EVAs require additional backroom staff to sit on console when they don't normally do so. Feb 16 '16 at 22:50
• If no EVAs were performed, but the crew was still trained for them, and the equipment was provided and kept ready, what would the difference in cost be? Feb 17 '16 at 1:09

## 1 Answer

Assuming that a person is already in space, the main costs are consumables lost (Small), and space suits (Larger). A space suit reportedly costs about $2 million. It's hard to tell how often they are used before being retired. One thing that can be tracked is the amount of supplies dedicated to EVAs launched by the Commercial Resupply missions to the ISS. • SpaceX CRS-2- 3 kg • SpaceX CRS-3- 173 kg • Orbital CRS-2- 39.4 kg • SpaceX CRS-4- 25 kg • Orbital CRS-3- 33 kg (Failed mission) • SpaceX CRS-5 23 kg These missions cover 2 years of time. I'm guessing that the large cargo on CRS-3 was a replacement space suit, and the rest are supplies required, maybe legs or arms, unique to each astronaut. There are 2 American space suits on the station at any one time, so let's say one every 4 years is good. Okay, all that being said, let's add up some costs. I'm going to use the total amount of the ISS related to EVA costs by the US as a starting point, over the 2 years. There are about 9 EVAs/year, always done in pairs. Assume half use the American suits. The cost per EVA per person is then about \$1.5 million. The far larger cost is in getting the astronaut to the ISS to take said spacewalk!