0

This file photo shows a Falcon 9 first stage being transported by truck after landing. There is some equipment at the end of the truck, which includes dials, knobs, and an exhaust stack, which suggests there may be a diesel generator, although it may just be a compressor for the hydraulics to its immediate right.

In fact, the big box may not necessarily be connected to the rocket is not related to the rocket at all, but it made me question if the rocket does have a need for any connected support equipment for the trip.

Question: What kinds of support equipment are necessary or at least important to transport the booster by truck? Are there chemicals, materials, or components that need to be kept cool for safety reasons, or things that need to be pressurized, or servos, valves, or actuators that need to be active?

below: Cropped screenshot from the YouTube video SpaceX - Booster Number 4 - Thaicom 8 06-06-2016. (@Hobbes linked to this discussion where I found this video.)

enter image description here

below: Image from the New York Times article Recycled Rockets Could Drop Costs, Speed Space Travel.

enter image description here

The recovered booster stage of a SpaceX Falcon 9 rocket that landed on a floating platform in May. Credit Loren Elliott for The New York Times

uhoh
  • 148,791
  • 53
  • 476
  • 1,473
  • 1
    The grey cable in the first image from the blue box on the trailer going to the end of the rocket could be a electrical connection. I suspect the gimbaled rocket engines need electrical energy during transport to prevent damages by vibration. The servos should keep the engines in neutral position parallel to the axis of the stage. Without energy the engines would hit the limit stop of the gimbal mechanism. – Uwe Apr 01 '17 at 18:07
  • @Uwe The image from the NYTimes (without those things) is supposed to be from May 2016 - the flight is not identified. I wonder if they forgot about it then, or if they used passive, static isolation instead, or perhaps the ride was shorter and they relied on on-board batteries? Hmm... this is evolving into a separate question! – uhoh Apr 01 '17 at 18:33
  • The engine gimbals are hydraulic (using RP-1), not electric. – Hobbes Apr 01 '17 at 18:36
  • IIRC the stage needs to be pressurized for flight loads, but no pressurization is necessary for transport. – Hobbes Apr 01 '17 at 18:37
  • @Hobbes I'm just thinking that driving in 100% humidity I might not mind a slight positive pressure of clean dry air (CDA) or nitrogen in some sensitive equipment compartments, and since barometric pressure can vary, I'd keep a slow CDA flow into the fuel tanks or other tanks - I'd want them closed to keep out the mosquitos, but if they were completely sealed, a rise in barometric pressure could expose the tanks to a negative differential. Of course I never took a road trip with a rocket, or got close to anything larger than this: https://i.stack.imgur.com/pIwP6.jpg – uhoh Apr 01 '17 at 19:01
  • @Hobbes who wants their satellite on a rocket who's carbon-fiber-overwrapped-aluminum Helium tank had experienced more pressure outside than inside, where even "tiny buckles" between the overwrap and metal can lead to "fast fires". I'd keep those tanks either in a controlled environment indoors, or slightly pressurized while on the highway to keep them clean, though the helium tanks should probably hold pressure by being valved off, and not require an external source of gas. – uhoh Apr 01 '17 at 19:02
  • 1
    But the hydraulic for engine gimbals might be controlled electronically. If not energized hydraulic valves are all open, position of the gimbaled engines might not be fixed. – Uwe Apr 01 '17 at 20:33
  • 1
    If the tanks for liquid oxygen are cleaned for compatibility with oxygen, no pollution with anything not compatible with liquid oxygen should be allowed. If the slight positive pressure in the tanks is lower than possible changes of air pressure, a regulation of pressure differential might be necessary. Pressure of the tanks might rise if heated by intensive sun during transport. – Uwe Apr 01 '17 at 20:43
  • I wish they could fit a few more wheels on that trailer. – Organic Marble Sep 07 '19 at 14:48
  • 1
    @OrganicMarble ha, it looks like half of them are not even touching the ground! – uhoh Sep 07 '19 at 14:50

1 Answers1

1

The big gray box attached to the end of the trailer is the power pack for the trailer. It powers the hydraulic jacks that raise/lower and rotate each axle. Depending on the trailer design, it could provide drive power for the trailer too, so it can maneuver at low speeds without a tractor unit.

Hobbes
  • 127,529
  • 4
  • 396
  • 565
  • I'll edit the question to further de-emphasize the box and the images. The title and text of the question asks what support is necessary for the rocket itself. – uhoh Apr 01 '17 at 10:54
  • 1
    There are two gas cylinders on the trailer that might be rocket-related. IIRC there's been a question about this before. – Hobbes Apr 01 '17 at 11:07
  • I can imagine there may be some places where a slight overpressure, or in other cases a slight flow of clean dry air might be a good idea. – uhoh Apr 01 '17 at 11:36
  • 1
    Gas cylinders were discussed not on SE, but NSF: https://forum.nasaspaceflight.com/index.php?topic=40393.800 – Hobbes Apr 01 '17 at 13:38
  • I've added a screenshot from the video in that discussion. I've also found out how to download the video in 4K resolution for future reference. The resolution is frightening - I didn't post it, but the boxes on the bottom and top can be "inspected" in greater detail. – uhoh Apr 01 '17 at 17:57