# RX (rocket family)

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). The propellant used is HTPB-based composite propellant.

## Individual boosters

This family is composed of:
| Version | Diameter (mm) | Length (m) | Thrust (kN) | Burn time (s) | Specific impulse (s) | Propellant mass (kg) | Total mass (kg) | Payload (kg) | Flights | Years active | Apogee reached (km) | Range reached (km) |
| RX-75 | 75 | | | | | | | | | | | |
| RX-100 | 100 | 1.90 | | 2.5 | | | 30 | | | | 7 | 11 |
| RX-1220 | 122 | | 19.6 | | | | | | | 2015-2019 | | 25 |
| RX-150 | 150 | | | | | | | | | | | |
| RX-250 | 250 | 5.30 | 53 | 6.0 | 220 | | 300 | 30–60 | 8 | 1987–2007 | 70–100 | |
| RX-320 | 320 | 4.74 | 52 | 9.0 | 220 | 371 | 532 | | 3 | 2008–2014 | 40–42 | |
| RX-420 | 420 | | 94 | 12.3 | 220 | 425 | | | 1 | 2009 | 43 | |
| RX-450 | 450 | 7.11 | 126 | 19.5 | 230 | 757-765 | 1718 | | 5 | 2015-2020 | 44-84 | 129 |
| RX-550 | 550 | | 255 | 14 | 240 | 1519 | | | | | | |
| RX-750 | 750 | | | | | | | | | | | |
| RX-980 | 980 | | | | | | | | | | | |
Note: Characteristics in italics are design values, they have not been measured yet.
RX-250 was launched eight times from 1987 to 2007. RX-320 was launched twice in 2008 and once again in 2014. RX-420 flew just once in 2009; it is superseded by RX-450 which was launched on 13 May 2015.
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. The RX 1220 is a based on the R-HAN122 B.
Two RX-1220 rockets were launched at the Karang Papak Air Force Base on December 23, 2018.
* RX (Roket Eksperimental) gallery
* RX-320
* RX-420
* RX-550

## Multi-stage rockets

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:
* RPS-01 Variant 1 (ex-RPS-420)
   * 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).
* RX-452
   * First stage: 1 x RX-400
   * Second stage: 1 x RX-450
   * Total height: 8.6 meters (28 ft)