11
$\begingroup$

JAXA's photo of Hayabusa-2's capsule, at its landing on 2020 Dec 6, shows that its parachute canopy had some non-opaque sections. Why?

Transparency has no advantage for this mission. Compared to conventional parachute materials, transparent ones of the same strength tend to be heavier and less flexible. Or were these sections actually mesh, perhaps for stability at high speed?

One unauthoritative report claims, without elaboration, perhaps extrapolating from some rough diagrams circulating online, that

A cross-type parachute is used by the vehicle.

JAXA photo of capsule

$\endgroup$
1
  • $\begingroup$ One theory might be that the parachute is laser-reflective on one surface only (the inner / lower one), so the transparent panels might be to increase the chance of a laser 'seeing' that surface. I have no evidence for this at all however. $\endgroup$ – tfb Dec 7 '20 at 14:34
4
$\begingroup$

To confirm @AlphaD's answer, here are some pictures of peregrine parachute (はやぶさ パラシュート) from a Japanese image search. (Peregrine isn't the kind of parachute, it's English for Hayabusa.)

They are called cross-form/cruciform parachutes and are used for payload deliveries.

hayabusa 1: enter image description here

hayabusa 2: enter image description here

enter image description here

development version: enter image description here

$\endgroup$
4
  • $\begingroup$ Yes, the photo of 2 says at top right "capsule ... parachute", but I can't figure out the kanji. What was the photo's source? $\endgroup$ – Camille Goudeseune Dec 8 '20 at 16:28
  • $\begingroup$ "Hayabusa 2" is at least sometimes written by JAXA as はやぶさ2. I don't see that here. $\endgroup$ – Camille Goudeseune Dec 8 '20 at 18:17
  • $\begingroup$ The photo is from here: twitter.com/KanenashiOpera_/status/1335800447467020288 $\endgroup$ – aliential Dec 8 '20 at 18:40
  • $\begingroup$ Thank you! That indeed mentions はやぶさ2 at least as a hash tag, and connects to the photo of the landed capsule, so I'll believe that the other photos showing the chute's mesh panels are authoritative. $\endgroup$ – Camille Goudeseune Dec 8 '20 at 18:54
7
$\begingroup$

Assuming that the design of the parachute was the same as that used on the first Hayabusa, the section you mention is actually netting. The following description of the parachute was given when the first Hayabusa was put on display to the public by JAXA (pdf summary in japanese):

パラシュート。強くて軽くてかさばらないポリエステル製の十字形の布でできていて、開くときに絡まないように十字以外の部分はネットが張られています。パラシュートは予定通り上空約5kmで開き、十数分かけて着地しました。

My rough translation:

Parachute. Strong and light polyester cloth in cross shape design. Netting is placed between the cross parts to prevent being entangled when deployed. Parachute opened as planned 5km above ground, and landed 10 minutes later.


Confirmation:

NHK reported that the design and creation of the parachute was handed to the same factory that produced the parachute for the first Hayabusa. It also confirmed that they based their parachute on the same structural design.

$\endgroup$
2
  • $\begingroup$ Any evidence that 2's parachute was similar? It opened higher up, I think, so its design might differ. $\endgroup$ – Camille Goudeseune Dec 8 '20 at 16:23
  • $\begingroup$ confirmation? $\endgroup$ – uhoh Dec 9 '20 at 7:03

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.