Sounding rocket in 3000 km at high altitude still find a rarefied atmosphere, it was felt that the atmosphere on the sector may be extended to around 6,400 km from the ground.

• 探空火箭在3000公里高空仍发现有稀薄大气，有人认为，大气层的上界可能延伸到离地面6400公里左右。