The RX rocket family (Roket Eksperimental, English: Experimental Rocket) is a series of solid-fuel rockets developed by the Indonesian National Institute of Aeronautics and Space (LAPAN).

They are simply named by their diameter in millimeters; for example, the RX-250 has a diameter of 250 millimeters (9.8 in).^[1] The propellant used is HTPB-based composite propellant.

This family is composed of:^{[2][3][4][5][6]}

Note: Characteristics in italics are design values, they have not been measured yet.

RX-250 was launched eight times from 1987 to 2007.^[4][7] RX-320 was launched twice in 2008^[4][8] and once again in 2014.^[9] RX-420 flew just once in 2009;^[10] it is superseded by RX-450 which was launched on 13 May 2015.^[11][12]

As of May 2016, the next booster version RX-550 is under construction; the larger ones are only on the drawing board.

In 2017 successful launches of RX 450 and RX 1220 were carried out from the Space and Atmospheric Observation & Technology Testing Center at Garut, West Java.^[13] The RX 1220 is a based on the R-HAN122 B.^[13]

Two RX-1220 rockets were launched at the Karang Papak Air Force Base on December 23, 2018.^[14]

• RX (Roket Eksperimental) gallery
• 
  RX-320
• 
  RX-420
• 
  RX-550

Once the solid boosters are fully qualified, LAPAN plans to assemble several of them into multi-stage rockets called Roket Pengorbit Satelit or RPS. Four staging configurations have been retained so far:^[15]

• RPS-01 Variant 1 (ex-RPS-420)^[16]

• First stage: 3 x RX-420
• Second stage: 1 x RX-420
• Third stage: 1 x RX-420 (shorter)
• Fourth stage: 1 x RX-320
• Total height: 10.00 meters (32.81 ft)

• RPS-01 Variant 2b

• First stage: 1 x RX-550 + 2 x RX-420
• Second stage: 1 x RX-550
• Third stage: 1 x RX-320
• Total height: 15.75 meters (51.7 ft)

• RPS-01 Variant 3a

• First stage: 1 x RX-450
• Second stage: 1 x RX-450
• Total height: 10.75 meters (35.3 ft)

• RPS-01 Variant 3b

• First stage: 1 x RX-450 + 2 x RX-320
• Second stage: 1 x RX-450
• Third stage: 1 x RX-320
• Total height: 11.75 meters (38.5 ft)

Earlier plans for the Pengorbitan-1 and -2 orbital launch vehicles (RPS-420s) were based on the RX-420 engine which was superseded by the RX-450. As of May 2016, integration work is proceeding on variants 3a and 3b, whose engines have all been successfully flight-qualified.

Since 2019, LAPAN's rocket division PUSTEKROKET has collaborated with AASPT and CGWIC of China in designing newer multiple stage sounding rockets. The new rockets will be called RX-452 which combined 400 millimeters (16 in) of first stage, and 450 millimeters (18 in) of second stage. The design is based on TK-32 sounding rocket as well as RX-450. It is expected the newer design to be able to reach above 100 kilometers (62 mi), simulation showed the rocket is able to reach 200 kilometers (120 mi).^[17]

• RX-452

• First stage: 1 x RX-400
• Second stage: 1 x RX-450
• Total height: 8.6 meters (28 ft)