NASASpaceFlight.com Forum

General Discussion => Q&A Section => Topic started by: a2soup on 04/17/2019 06:46 pm

Title: ISS ammonia Q&A
Post by: a2soup on 04/17/2019 06:46 pm

I was wondering about the supply of ammonia on the ISS. The ISS has had a few major ammonia leaks in its history, and seems to leak small amounts of ammonia frequently. Is there any way to resupply the ammonia? Is there a significant reserve on board to replenish what is lost to leaks? Or will too much ammonia loss over time shut down the station permanently?

Title: Re: ISS ammonia Q&A
Post by: SWGlassPit on 04/18/2019 02:31 pm

There is a reserve of ammonia present in two installed Ammonia Tank Assemblies (ATAs), situated on the back of the P1 and S1 trusses.  Additionally, there are two spare ATAs situated on pallets ELC1 and ELC3.  Furthermore, NASA has retained the capability to build and launch additional ATAs, should it become necessary.

Title: Re: ISS ammonia Q&A
Post by: brickmack on 04/18/2019 05:04 pm

The ATAs are 201x117x140 cm and about 510 kg, so Dragon or HTV should be able to carry one up if needed

Title: Re: ISS ammonia Q&A
Post by: Sam Ho on 04/18/2019 06:42 pm

Fresh ATAs were brought up near the end of the Shuttle program, on STS-128 and STS-131.

https://www.nasaspaceflight.com/2009/09/eva-2-ammonia-tank-replacement-dat-tps-clearance-rationale/
https://www.nasaspaceflight.com/2010/04/eva-2-ata-replacement-previou-eva-issues-reviewed/