# What is a propellant burner trailer?

CNN and NPR have pointed out that the US president recently tweeted a surveillance photo of an explosion of a rocket on a launch pad.

One of the items identified in the photo is labeled as a propellant burner trailer.

Question: What is a propellant burner, and why would it be in a trailer?

• – uhoh Aug 31 '19 at 0:31

This answer is largely speculative but based upon knowledge of similar systems.

1. The Safir space launch vehicle may use hypergolic propellants.
2. The launch site shown in the photograph has minimal permanent infrastructure.
3. Hypergolic propellant storage facilities at Johnson Space Center and White Sands Test Facility have burner stacks to safely dispose of vented propellants. (KSC-2010-045R, pages 53 and 44).

Speculative conclusion: the trailer is (was) a portable means of storing the vehicle's propellants and is (was) equipped with burner stacks to safely dispose of vented propellant.

(Crop of largest version of picture I could find, showing possible tanks in the trailer. from "The Drive")

• Some sources say the propellant is UDMH with IRFNA, which are probably a little less nasty when combined and burned than they are separately. – Russell Borogove Aug 31 '19 at 1:12
• @RussellBorogove thanks, I will soften up point 1. – Organic Marble Aug 31 '19 at 1:14
• Soften? The article you linked suggested (either UDMH or hydrocarbon) + unnamed storable oxidizer; I was just passing along that other sources suggest that IRFNA is the oxidizer and support the UDMH end of the speculation. – Russell Borogove Aug 31 '19 at 1:15
• Are IRFNA and UDMH hypergolic? I don't know, so was trying to avoid claiming that they are. – Organic Marble Aug 31 '19 at 1:16
• Oh yeah they are. – Russell Borogove Aug 31 '19 at 1:18