Unexpected issues with Soyuz-MS caused postponing launch of Soyuz-MS which should delivered members of Expedition 48-49 to ISS on 24th June 2016.
It seems that Astronauts Kathleen Rubins (NASA-first spaceflight), Takuya Onishi (JAXA-first spaceflight) and cosmonaut Anatoli Ivanishin (Roscosmos-second spaceflight) will start their space mission on International Space Station two weeks later. It was not unveiled if launch delay will effect on mission duration, originally planned to last until November 2016. All three members of crew already finished their training in Star City in Russia on 27 May 2016. It is planned that Astronauts Kathleen Rubins, Takuya Onishi (JAXA-first spaceflight) and Anatoli Ivanishin will start their flight preparations in Baikonur on 24th June 2016. Launch of the Soyuz-MS on atop of Soyuz-FG was rescheduled for 7th July 2016 but it is possible that it will be postponed further, even to 17th July 2016.
On picture above: Kathleen Rubins, Anatoli Ivanishin, Takuya Onishi.
According to Russian media delay is caused by problems with Soyuz-MS. It is new version of Soyuz spacecraft designed and manufactured by RKK Energia. It is successor of Soyuz-TMA; flight with members of Expedition 48-49 onboard was planned as maiden flight of MS version. Problems were announced on June 1, 2016 and were confirmed by source close to Russian space industry. According to TASS, Soyuz-MS could create threat for ISS after docking. New control system could cause rolling of the docked Soyuz-MS without possibility of stopping this movement from International Space Station, crew remaining inside Soyuz or ground control center. It is obviously that it would be danger for crew inside Soyuz and ISS - rolling spacecraft could easily destroy docking port or effect of stability of flight of ISS. Experts in RKK Energia are working on problem but still reasons of potential anomaly are not known – it could be assumed that new docking system and modified KURS docking navigation system is possible source of anomaly.
Comparing to previous versions of Soyuz, MS version offers multiple improvements. New more efficient solar arrays were installed along with new docking systems (including KURS docking navigation system). Energia decided to modify onboard computer for digital computer (instead analog Argon-16) TsVM-101 , which is lighter and smaller; MBITS telemetry transferring system is increasing safety during docking if ground stations are out of range (it relays telemetry data using satellites). GLONASS/GPS/COSPAS-SARSAT navigation and rescue systems provide more accurate data for recovering after landing.